Asymmetric hose coupling endform for fluid transfer assemblies

ABSTRACT

An endform connector having an axial bore through which a fluid is conveyed comprising: a rigid tubular member having a first end, a second end, an annular channel having an inner diameter extending from the first end to the second end through which a fluid is transported, a stem portion extending a fixed distance from the first end, and at least one sealing member extending outward from the stem portion forming a surface having a tapered profile terminating in an outwardly extending rim, which exhibits an asymmetric perimeter adapted to be inserted into an inner channel of a fluid transport hose, wherein the endform connector is sealed to a fluid transport hose; and a connector portion on the second end adapted to be coupled with a second fluid conveying structure, and a method for assembling an endform connector to a hose are described.

BACKGROUND OF THE INVENTION

The present invention relates to a coupler device for hose connectionsand to a method for connecting such endform to a hose. Moreparticularly, the present invention relates to a coupling endform deviceincluding a barb having an asymmetric barb profile which providesimproved coupling retention and sealing properties while requiring noadditional coupling effort during assembly of the coupling device to ahose, compared to a conventional coupling device having a symmetricalcircular barb profile.

Hose coupling endform devices are known. For example, commonly assignedU.S. patent application Ser. No. 10/410,973 to Mobley teaches a couplingdevice for connecting a polymeric tubing having a first conductive innersurface to the open end of a hose having a second conductive surfacesuch that conductive continuity is maintained between the polymeric tubeand the hose. U.S. Pat. No. 3,653,692 to Henson describes an elastomerichose connected to a nipple having a circumferential barb. The hose isstretched allowing a ring member to slide down the hose and over thebarbed nipple where it creates a compression on the hose when the hoseis no longer stretched. U.S. Pat. No. 6,733,047 to Stieler; U.S. Pat.No. 6,637,779 to Andre; U.S. Pat. No. 6,634,679 to Stieler; U.S. Pat.No. 6,568,714 to Stripe; U.S. Pat. No. 6,412,826 to Kulevsky, et al;U.S. Pat. No. 6,378,908 to Walker, et al.; U.S. Pat. No. 6,113,151 toBeans; U.S. Pat. No. 5,711,549 to Beans; U.S. Pat. No. 5,707,087 toRidenour et al; U.S. Pat. No. 5,516,157 to Williamson; U.S. Pat. No.5,516,156 Williamson; U.S. Pat. No. 5,423,581 to Saylers; U.S. Pat. No.4,114,930 to Perkins et al; and U.S. Pat. No. 3,689,111 to Osmun, allteach coupling devices for connection tubing to a fitting assembly toprevent leaks in a fluid transport system.

It is essential that fluid transfer hoses such as those employed influid transfer assemblies on power steering pressure and return linesexhibit tight tolerances and high strength to prevent the fluid fromleaking from the assembly. Current practice in the hose connector artrequires that a heavy clamping or crimping force be applied about acollar around the hose and the fitting to provide a fluid-tight seal andto provide pull-off resistance to the assembly. In such cases, the hoseis compressed radially inward to make a seal. However, it is difficultto make a leak-tight seal, because the tube, even though malleable,tends to have enough elasticity to relax and deform upon release of theclamping or crimping pressure sufficient to compromise the fluid-tightseal, particularly, when the fluid is under high pressure for anextended period of time. Therefore, while conventional connectorsgenerally are able to achieve the required tolerances or the strengthrequired to provide good sealing and hose retention properties, theseproperties are generally accompanied by undesirable high assemblyeffort. For example, in a fluid transfer assembly designed to achievelow push-on force throughout its dimensional tolerance, will have a highprobability of poor to mediocre coupling tensile, burst and impulseperformance.

Accordingly, it would be advantageous to provide a hose endformconnector that would increase coupling retention using both clamped andcrimped assembly design while requiring reduced assembly effort force.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a hose couplingendform having improved coupling retention and sealing properties withno effect on assembly effort.

It is another object of the invention to provide a method of assemblinga hose endform connector to a hose whereby coupling retention isimproved and assembly effort is unaffected.

In accordance with the present invention, a hose endform connector isdescribed for use in connecting a fluid transfer hose thereto in amanner which provides a leak-free fluid transfer assembly havingincreased coupling retention while not increasing the assembly effortforce required in prior art hose endform connection assemblies. The hoseendform connector comprises a rigid tubular member having a first endand a second end. The hose endform connector has an annular channelextending from the first end to the second end. The annular channelexhibits an inner diameter extending along its longitudinal axis fortransporting a fluid therethrough. The rigid tubular member furthercomprises a stem portion defining the first end of the rigid tubularmember. The stem portion has a uniform annular outer surface diameterextending a predetermined distance from the end of the hose endformconnector, wherein the uniform annular surface is adapted to be insertedinto an open ended channel of a hose. The stem portion further includesat least one sealing member extending outward from the outer surfacediameter of the stem portion in a direction toward the second end toform a radially increasing surface having a tapered profile. The taperedsurface terminates in an outward rim having an asymmetrical shape. Theopposite side of the tapered surface of the sealing means exhibits anannular surface which is perpendicular or near perpendicular to therigid tubular member. The asymmetric shape of the outer perimeter of thesealing member increases coupling tensile (axial force) by as much as92% leaving assembly effort unaffected.

The second end portion includes a tubular structure which may include anannular ridge or ring suitable for connecting the second end to anothertubular structure, such as by a quick-connect/disconnect device.

In accordance with the present invention, the metal fitting is looselyinserted into the open end of the hose where it is joined to the tube ina fluid-tight seal created by crimping, swaging, rolling or other meansof securing the hose around the metal barbed fitting. The fluid-tightseal is created by the high pressure of the metal annular barbs pressedagainst the inner diameter of the hose.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a longitudinal side view of an endform tube connector of theprior art ready for assembly with a hose;

FIG. 2 a is a cross-sectional end view of the endform tube connector ofFIG. 1;

FIG. 2 b is a cross-sectional end view of an endform tube connector ofthe prior art;

FIG. 3 a is a graph illustrating the coupling tensile force of anendform connector of the present invention.

FIG. 3 b is a graph illustrating the coupling tensile force of anendform connector of the prior art.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that a hose endform connector having an arrowhead barbconfigured to exhibit an asymmetric perimeter rather than a symmetriccircular perimeter provides significantly improved tensile values.Furthermore the asymmetric barb exhibits significantly less sensitivity(more robust) to crimp diameter variability, hose dimensionalvariability, etc., while maintaining an overall equivalent performancewith respect to both inside and outside diameter of the hose to whichthe coupler is assembled as well as exhibiting no increase in push-onforce in assembling the endform connector to a hose.

The basic concept of the present invention is to change the shape of theouter perimeter of the arrowhead barb from a symmetrical circular shapeto an asymmetric shape by offsetting the shape of the arrowhead barb andcreating a larger interference between the stem land diameter and thearrowhead barb diameter. More specifically, the coupling retention isincreased using both clamped and crimped assembly design formats, whilemaintaining equivalent assembly effort force.

The advantage of the asymmetric arrowhead barb design over theconventional symmetrical circular arrowhead barb is as follows:

-   -   push-on force is not increased.    -   Coupling tensile (axial force) is enhanced up to about 92%.    -   Peak coupling tensile (axial force) is maintained over a wider        tolerance.

The potential applications for the endform connectors having theasymmetrical configuration of the present invention include assembliesfor automotive and other mechanical applications, such as in powersteering, transmission, oil cooler, and other fluid transport assembliesrequiring high pressures.

FIGS. 1 and 2 illustrate a hose endform connector of the presentinvention used to connect an end form connector to a polymeric hose. Asshown in FIG. 1, the endform connector 10 includes a tubular body 12having a first end 14 and a second end 16. An annular channel 18 extendsalong longitudinal axis X from the first end 14 to the second end 16.The tubular body 12 includes a stem portion 20 and a sealing member 22adjacent the first end 14 of the tubular body 12. The stem portion 20and the sealing member 22 are adapted to inserted into an open channel24 of a hose 26 to secure the hose 26 to the endform connector 10 toprovide a leak-free connection. The stem portion 20 has a uniform outerannular surface 28 extending a fixed distance from the first end 14 ofthe tubular body 12. The sealing member 22 extends outwardly from theouter annular surface 28 of the stem portion 20 to form a radiallyincreasing surface 30 having a tapered profile. The radially increasingsurface 30 of the sealing member 22 terminates in a rim 32 exhibiting anasymmetrical perimeter. The sealing member 22 includes a rearwardsurface 34 lying in a plane perpendicular to or nearly perpendicular tothe orientation of the tubular body 12. The rearward surface 34 of thesealing member 22 extends radially outward from the tubular body 12 andterminates with the rim 32 exhibiting an asymmetric perimeter.Typically, the rearward surface 34 may be tapered at an angle of up toabout 5°, preferably, about 0 to 3° and most preferably, about 0 to 2°,with respect to the vertical orientation of the rearward surface 34. Thestem portion 20 is adapted to be inserted into an open end 24 of a hose26 to provide a leak-free fitting. FIG. 2 shows a cross-sectional viewof the endform connector of FIG. 1, wherein the rim 32 of the sealingmember 22 is shown as having an asymmetric configuration while theannular channel 18 of the tubular body has a circular configuration.

When the metal endform connector 10 is inserted into the open end of thehose 26, sufficient pressure is exerted upon the hose 26 to radiallycompress the hose 26 inward around the stem portion 20 of the endfitting 10 such that the open channel 24 of the hose 26 engages thesealing member 22 providing a leak-free seal in the fuel transportassembly. The sealing members 22 not only provide leak-free seals butthey also increase or maintain the pull-off resistance of the hose 26from the endform connector 10.

The number of sealing members on the endform connector is not critical.One sealing member in the form of an arrowhead barb is sufficient inmost application; however, it may be desirable to include more than onesealing member at fixed intervals along the stem portion of the endformconnector. In those instances where more than one sealing member isemployed, It may be desirable to alter the rotational position of themore than one sealing members to exhibit a non-linear orientation of theasymmetrical rims so that the symmetry of the more than one arrowheadbarbs are not in a linear relationship.

The materials used to form the endform connector should be of a lowcorrosion tolerance material. In one embodiment the endform connector isformed from a metal, such as steel or the like, or it is formed from aceramic material or a rigid plastic. Such materials should be highquality and free from voids, pits, laps cracks, folds, seams and otherdefects. It is within the context of the present invention to treat themetal or ceramic endform connectors, especially the arrowhead barbs toprotect them from the environment. The endform members may be coatedwith a polymeric material 36 (FIG. 1) such as nylon, or it may beelectroplated, painted or similarly treated. In another embodiment, theendform may be formed completely from a plastic material.

EXAMPLE 1

SAMPLE 1—A first endform connector having an asymmetric shaped arrowheadbarb in accordance with the present invention, and a fluid transporthose were assembled to determine coupling tensile values, robustcharacteristics, and push-on force.

COMPARATIVE SAMPLE 2—A second endform connector having a circular shapedarrowhead barb in accordance with the prior art, and a fluid transporthose were assembled to determine coupling tensile, robustcharacteristics, and push-on force.

Regarding SAMPLE 1, the prediction trace yields the following insightwith respect to coupling tensile performance:

-   -   Hose 3209 yields higher tensile values than hose 3039.    -   Coupling tensile values drop as hose ID increases.    -   Coupling tensile values drop significantly as the “%        compression” of the crimped assembly decreases.    -   Asymmetrical stem and symmetric stem yield approximately equal        tensile values at high compression.    -   Symmetric barb is very sensitive to crimp compression as        evidenced by the slope of the “% compression” factor traces).

Regarding SAMPLE 2, the prediction trace yields the following insightwith regard to the asymmetric coupling tensile performance:

-   -   Overall equivalent performance of each stem with respect to the        following factors: Hose, OD, and ID.    -   The slope of the “% compression” factor is near zero, indicating        that the asymmetric stem is much less sensitive (more robust) to        crimp diameter variability, hose dimensional variability, etc.

Although the present invention has been fully described in connectionwith a preferred embodiment thereof and with reference to theaccompanying drawings, various changes and modifications will occur tothose skilled in the art. Accordingly, such changes and modificationsare to be understood as being within the scope of the present inventionas defined by the appended claims.

1. An endform connector having an axial bore for conveying a fluid, saidendform connector comprising: a rigid tubular member having a first end,a second end, an annular channel having an inner diameter extending fromsaid first end to said second end providing a path through which a fluidis transported, a stem portion extending a fixed distance from saidfirst end, and at least one sealing member extending outward from saidstem portion forming a surface having a tapered profile, said surfacehaving said tapered profile terminating in an outwardly extending rim,said outwardly extending rim exhibiting an asymmetric perimeter adaptedto be inserted into an inner channel of one end of a fluid transporthose, wherein said one end of said fluid transport hose is seal ablysecured to said to said extending rim exhibiting an asymmetricperimeter; and a connector portion on said second end, said connectorportion adapted to be coupled with a second fluid conveying structure.2. The endform connector of claim 1 wherein said at least one sealingmember is an arrowhead barb.
 3. The endform connector of claim 1,wherein said at least one sealing member includes an annular surfaceopposite said tapered surface, said annular surface extendingperpendicularly relative to said rigid tubular member.
 4. The endformconnector of claim 1, wherein said rim exhibiting said asymmetricperimeter has a sharp edge.
 5. The endform connector of claim 1, whereinsaid hose is uniformly deformed onto and around said at least onesealing member to create a leak-free seal therebetween.
 6. The endformconnector of claim 1 wherein said endform connector is made from amaterial selected from the group consisting of metal, ceramic andplastic.
 7. The endform connector of claim 6, wherein said endform ismetal.
 8. The endform connector of claim 7, wherein said metal is steel.9. The endform connector of claim 1, wherein said metal endformconnector is pre-coated with a protecting material to protect saidendform connector from environmental conditions.
 10. The endformconnector of claim 9, wherein said protective material is nylon.
 11. Theendform connector of claim 1, wherein said second fluid conveyingstructure is a quick connect/quick disconnect coupling.
 12. A method forcoupling an endform connector to a hose to provide a leak-free sealbetween said endform connector and said hose wherein said couplingexhibits reduced push-on effort, said method comprising; providing anendform connector, said endform connector comprising: a rigid tubularmember having a first end, a second end, an annular channel having aninner diameter extending from said first end to said second end throughwhich a fluid is transported: a stem portion extending a fixed distancefrom said first end: at least one sealing member extending outward fromsaid stem portion forming a surface having a tapered profile, saidsurface having said tapered profile terminating in an outwardlyextending rim, said outwardly extending rim exhibiting an asymmetricperimeter adapted to be inserted into an inner channel of a fluidtransport hose; and a connector portion on said second end, saidconnector portion adapted to be coupled with a second fluid conveyingstructure; providing a fluid transport hose having a first end, a secondend and an annular inner surface forming an inner channel fortransporting a fluid therethrough; inserting said outwardly extendingrim exhibiting said asymmetric perimeter into one end of said fluidtransport hose; and sealably securing said one end of said fluidtransport hose to said outwardly extending rim exhibiting saidasymmetric perimeter inserted therein.
 13. The method of claim 12,wherein said endform connector is made from a rigid material selectedfrom the group consisting of metal, ceramic or plastic.
 14. The methodof claim 13, wherein said endform connector is made from metal.
 15. Themethod of claim 14, wherein said metal is steel.
 16. The method of claim12, wherein said sealing member includes an annular surface oppositesaid tapered surface, said annular surface extending perpendicularlyfrom said rigid tubular member.
 17. The method of claim 12, wherein saidrim exhibiting said asymmetric perimeter has a sharp edge.
 18. Themethod of claim 12, wherein said endform connector is pre-coated with aprotecting material to protect said endform connector from environmentalconditions.
 19. The method of claim 18, wherein said protective materialis nylon.
 20. In a method of assembling an endform connector to a hosein a fluid transport assembly, the improvement which comprises:providing an endform connector, said endform connector comprising asteel tubular member having a first end, a second end, an annularchannel having an inner diameter extending from said first end to saidsecond end through which a fluid is transported, a stem portionextending a fixed distance from said first end, and at least one sealingmember extending outward from said stem portion forming a surface havinga tapered profile, said surface having said tapered profile terminatingin an outwardly extending rim, said outwardly extending rim exhibitingan asymmetric perimeter having a sharp edge, said tapered surfaceadapted to be inserted into an inner channel of a fluid transport hose;and a connector portion on said second end, said connector portionadapted to be coupled with a second fluid conveying structure; providinga fluid transport hose having a first end, a second end and an annularinner surface forming an inner channel for transporting a fluidtherethrough; inserting said outwardly extending rim exhibiting saidasymmetric perimeter into one of said first end and said second end ofsaid hose; and sealably securing said one end of said fluid transporthose to said outwardly extending rim exhibiting said asymmetricperimeter inserted therein.